Manchester City manager Pep Guardiola said even he is surprised by Gabriel Jesus' stunning start in English soccer.

The 19-year-old bagged a brace on his full home debut to earn City a 2-1 win over Swansea on Sunday.

After arriving in England at the start of last month, the Brazilian is emerging as one of the most exciting prospects to land in the English top flight for some time, and has tallied three goals in his first two Premier League starts.

"Yes, I'm surprised," said Guardiola, whose side climbed to third place in the standings, 10 points behind leader Chelsea.

"When he came here after he finished the season and won the (Brazilian) championship with Palmeiras, we spoke.

"The last two or three years he never had a break because Brazil played a lot of games. I said, 'Take your time, come back when you feel you're ready.'

"But he's 19 years old. Brazilian guys are physically strong and he only needed a few training sessions to be ready.

"The guy told me he is never tired, always healthy and recovers quickly. We need to protect him, but everybody is surprised at his level."

Jesus netted an 11th-minute close-range volley and gave City victory in the second minute of stoppage time after Gylfi Sigurdsson equalized for the Swans with nine minutes left.

"In the box, he is something special with the ball," Guardiola added of Jesus.

"It is clear how his first touch is good. With his second, third, he needs to improve, but without the ball he is involved.

"He is so intelligent, knows when to put pressure on the central defenders.

"Some guys need a lot of time to settle, to know the league and their teammates. Others settle immediately, and that's how this guy arrived."

Jesus revealed at the weekend that a personal phone-call from Guardiola helped seal his $33.6 million City move, which was completed last month.

"When we buy a player, we expect the best for our decisions," Guardiola said.

"We take a lot of decisions every five minutes. We take and you judge, but always judge after, not judge before.

"Sometimes we are right and sometimes not. We are so delighted because most of the big important clubs in Europe wanted him and he decided to come here.

"We expect the best because he is a striker for Brazil and it is not easy to play for the Brazil national team.

"Suddenly he arrives and you have to play immediately. Eight minutes against Tottenham and you think, 'Wow.' I think he is hungry and has desire and shows so many good things."

Swans boss Paul Clement was unhappy with the freekick that led to City's winner.

"My opinion was it wasn't a foul," he said.

"(Luciano) Narsingh tried to evade the challenge of (Aleksandar) Kolarov and the linesman gave the decision.

"Then the restart was 10 meters deeper than where the freekick was, in a more central position and the ball was rolling.

"Those were things the referee was picking up on all game."